The Effect of Lead Exposure on Selected Blood Inflammatory Biomarkers in Guinea pigs

A fire involving an electric service transformer and its cooling fluid, a mixture of PCBs and chlorinated benzenes, contaminated an office building with a fine soot. Chemical analysis showed PCDDs and PCDFs including the highly toxic tetra isomers. Guinea pigs were chosen as an experimental animal to test the soot's toxicity because of their sensitivity to these compounds, and the liver was examined because it is a target organ. The soot was suspended in 0.75% methyl cellulose and administered in a single dose by gavage at levels of 1,10,100, and 500mgm soot/kgm body weight. Each dose group was composed of 6 males and 6 females. Control groups included 12 (6 male, 6 female) animals fed activated carbon in methyl cellulose, 6 males fed methyl cellulose, and 16 males and 10 females untreated. The guinea pigs were sacrificed at 42 days by suffocation in CO2. Liver samples were immediately immersed and minced in 2% gluteraldehyde in cacadylate buffer at pH 7.4 and 4°C. After overnight fixation, samples were postfixed in 1% OsO4 in cacodylate for 1 hr at room temperature, embedded in epon, sectioned and stained with uranyl acetate and lead citrate.

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Glycogen in guinea pig neutrophils: Ultrastructural study of neutrophils at the intradermal site of BCG injection

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100077207 ◽

1983 ◽

Vol 41 ◽

pp. 726-727

Author(s):

Corazon D. Bucana

Keyword(s):

Bone Marrow ◽

Guinea Pig ◽

Electron Density ◽

Peritoneal Cavity ◽

Ultrastructural Study ◽

Guinea Pigs ◽

Random Distribution ◽

Glycogen Content ◽

Polymorphonuclear Neutrophils ◽

Ultrastructural Studies

In the circulating blood of man and guinea pigs, glycogen occurs primarily in polymorphonuclear neutrophils and platelets. The amount of glycogen in neutrophils increases with time after the cells leave the bone marrow, and the distribution of glycogen in neutrophils changes from an apparently random distribution to large clumps when these cells move out of the circulation to the site of inflammation in the peritoneal cavity. The objective of this study was to further investigate changes in glycogen content and distribution in neutrophils. I chose an intradermal site because it allows study of neutrophils at various stages of extravasation.Initially, osmium ferrocyanide and osmium ferricyanide were used to fix glycogen in the neutrophils for ultrastructural studies. My findings confirmed previous reports that showed that glycogen is well preserved by both these fixatives and that osmium ferricyanide protects glycogen from solubilization by uranyl acetate.I found that osmium ferrocyanide similarly protected glycogen. My studies showed, however, that the electron density of mitochondria and other cytoplasmic organelles was lower in samples fixed with osmium ferrocyanide than in samples fixed with osmium ferricyanide.

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Densitometric Identification of Primitive Erythroblasts After Reaction With Diaminobenzidine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072083 ◽

1973 ◽

Vol 31 ◽

pp. 328-329

Author(s):

John A. Trotter

Keyword(s):

Red Blood Cells ◽

Analytical Method ◽

Blood Cells ◽

Guinea Pigs ◽

Specific Protein ◽

Visual Examination ◽

Hemoglobin Synthesis ◽

Peroxidatic Activity ◽

Small Density

Hemoglobin is the specific protein of red blood cells. Those cells in which hemoglobin synthesis is initiated are the earliest cells that can presently be considered to be committed to erythropoiesis. In order to identify such early cells electron microscopically, we have made use of the peroxidatic activity of hemoglobin by reacting the marrow of erythropoietically stimulated guinea pigs with diaminobenzidine (DAB). The reaction product appeared as a diffuse and amorphous electron opacity throughout the cytoplasm of reactive cells. The detection of small density increases of such a diffuse nature required an analytical method more sensitive and reliable than the visual examination of micrographs. A procedure was therefore devised for the evaluation of micrographs (negatives) with a densitometer (Weston Photographic Analyzer).

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